The present invention relates, in general, to integrated circuits and, more particularly, to a power conversion integrated circuit.
A power supply is controlled to be either on or off by a mechanical switch or a relay. Typically, additional discrete components that are external to the integrated circuit adapt the power supply for use in applications such as cable converters for television sets, computer monitors, video cassette recorders (VCRs), battery chargers for portable communications devices, computer printers, and other electronic systems.
Depending on the particular application, the on/off circuitry of a power supply control circuit includes components such as opto-couplers, latches, resistors, and capacitors. Monolithic circuit integration minimizes the number of components external to the integrated circuit and reduces the cost of power supplies. The number and types of external components along with the cost of the integrated circuit package provide functionality that differentiates among different power supplies. Typically, a switching regulator without on/off circuitry is manufactured in a three pin package. A drawback of these three pin package configurations is that they offer limited functionality within the package.
Accordingly, it would be advantageous to have an inexpensive integrated power supply controller that is capable of operating with many different power supplies. It would be of further advantage for the power supply controller to have a minimal number of discrete external components for controlling the power supply on/off switch circuitry.